Core-lifter for annular rock-drills



(No Model.)

G. P. CASE.

GORE LIFTER FOR ANNULAR BOOK DRILLS.

No. 247,303. Patented Sept. 20,1881;

- Fly] F5913. Ef

UNITED STATES PATENT OFFICE.

GEORGE F. CASE, OF OLAREMONT, NEW HAMPSHIRE.

CORE -LIFTER FOR ANNULAR RO CK-DRILLS.

SPECIFICATION forming part of Letters Patent No. 247,303, dated September 20, 1881.

Application filed August 8, 1881.

To all whom it may concern Be it known that I, GEORGE F. CASE, of Glaremont, in the county of Sullivan and State of New Hampshire, have invented a new and Improved Gore-Lifter for Annular Rock-Drills and I do hereby declare that the following is a full and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon. This invention relates to an improvement in core-lifters for annular rock-drills; and it consists in making a tapering recess in the tubing next above the drill-head in such a way that the bottom of the coupling and the top of the drill-head make upper and lower shoulders to such recess, and in combining with such recess a splitspringtube, into which wedges are fitted loosely, all as more fully hereinafter described. To enable those skilled in the art to know how to make and use my invention, I will proceed to fully describe the same, reference being had to the accompanying drawings, in which- Figure l is a longitudinal section of the corelifter and annular drill to which it is applied; Fig. 2, a transverse section of the spring-tube on the line 00w ofFig. l,with the wedges inserted; Fig. 3, a detail view ofthe spring-tube with the openings cut therein, and Fig. 4 a detail view of one of the wedges.

Like letters denote corresponding parts in each figure.

A represents the drill-head screwed into the section of tubing B, which, in turn, is connected to the drill-rod by the coupling 0. The inner side of the tubing B is made tapering, decreasing in size downwardly, thus forming a recess, 0, in said tubing, as shown in Fig. 1. The lower end of the coupling 0 terminates at the larger and upper end of the recess, there forming a shoulder, a, and the upper end of the drill-head in like manner terminates at the lower and smaller end of said recess, thusforming a shoulder, 1). Within this recess the spring-tube D and its wedges cl have movement up and down, which movement is terminated in either direction by the shoulders at b. The spring-tube D, split from end to end, so as to allow of sufficient contraction and expansion, has two or more (No model.)

openings, d, as may be desired, cut in its sides, of sufficient length and width to receive and hold loosely the wedges 01, one of these openings being shown in Fig. 3. The wedges d are of the construction shown in Fig. 4, the outward projection thereon being the portion that enters the opening d of the spring-tube and clamps the core, as may be seen by reference to Fig. 1. These wedges should be made of hardened steel or iron, while the tube can be of spring temper. There should be enough space left between the outer sides of the wedges and the tapering sides of the recess to allow the drill to revolve without revolving the tube, the wedges of which, by the spring of the tube, are pressed against the core. There should also bespace enough in the openings at of the springtube to permit the wedges to have plenty of play in said openings.

In its operation the spring-tube D hugs the core, but allows it to pass up through it, the tube moving with ittoward the upper and larger part of the recess, and prevented from revolution by its spring contact with the core. When the ring comes in contact with the shoulder a of coupling 0 it stops and there remains until the required depth is reached and it is desired to break off the core. When the drill-rod is raised the movement causes the wedges to be drawnintothe smaller end of the recess, clampingit firmly against the core and breaking off the core, which is raised with the drill-rod and easily removed therefrom in the ordinary manner.

I am aware that core-lifters have been invented wherein a tapering recess with shoul ders was made in a section of the tubing, but such recesses are expensive to make if turned up smoothly, as they should be 5 and also that in such recesses cut-steel rings have been used as core-lifters, such rings having thick portions armed with rough diamonds or carbon, but such rings are expensive and soon get out of order. In the invention herein described both of these inconveniences are avoided.

The recess in the tubing can be bored or planed out smoothly without difficulty, and the wear of the core-lifter comes upon the wedges,

which are Very hard, and from their form may wear a long time and remain effective, and finally may be removed at a small expense.

Havingdescribed myinventiomwhatl claim 1S- n 1. In combination with the drill-head A and the coupling 0, forming, upper and lower shoulders, the intermediate recessed tubing, B, substantially as described.

2. Ineombination with the recessed tubing B, the split spring-tube I), having wedges d, constructed and arranged substantially as described.

This specification signed and witnessed this 16th day of May 1881.

G. F. CASE.

Witnesses:

I. DUNCAN UPHAM, HERM N HALL, JAMES L. R1012. 

